17.tests

tests1.rs

// tests1.rs
//
// Tests are important to ensure that your code does what you think it should
// do. Tests can be run on this file with the following command: rustlings run
// tests1
//
// This test has a problem with it -- make the test compile! Make the test pass!
// Make the test fail!
//
// Execute `rustlings hint tests1` or use the `hint` watch subcommand for a
// hint.


#[cfg(test)]
mod tests {
    #[test]
    fn you_can_assert() {
        assert!(true);
    }
}

tests2.rs

Github solution link

// tests2.rs
//
// This test has a problem with it -- make the test compile! Make the test pass!
// Make the test fail!
//
// Execute `rustlings hint tests2` or use the `hint` watch subcommand for a
// hint.


#[cfg(test)]
mod tests {
    #[test]
    fn you_can_assert_eq() {
        assert_eq!(1, 1);
    }
}

tests3.rs

Github solution link

// tests3.rs
//
// This test isn't testing our function -- make it do that in such a way that
// the test passes. Then write a second test that tests whether we get the
// result we expect to get when we call `is_even(5)`.
//
// Execute `rustlings hint tests3` or use the `hint` watch subcommand for a
// hint.


pub fn is_even(num: i32) -> bool {
    num % 2 == 0
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn is_true_when_even() {
        assert!(is_even(4));
    }

    #[test]
    fn is_false_when_odd() {
        assert!(!is_even(5));
    }
}

tests4.rs

Github solution link

// tests4.rs
//
// Make sure that we're testing for the correct conditions!
//
// Execute `rustlings hint tests4` or use the `hint` watch subcommand for a
// hint.


struct Rectangle {
    width: i32,
    height: i32
}

impl Rectangle {
    // Only change the test functions themselves
    pub fn new(width: i32, height: i32) -> Result<Rectangle, String> {
        if width <= 0 || height <= 0 {
            Err(String::from("Rectangle width and height cannot be negative!"))
        } else {
            Ok(Rectangle {width, height})
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn correct_width_and_height() {
        // This test should check if the rectangle is the size that we pass into its constructor
        let rect = Rectangle::new(10, 20).unwrap();
        assert_eq!(rect.width, 10); // check width
        assert_eq!(rect.height, 20); // check height
    }

    #[test]
    fn negative_width() {
        // This test should check if program panics when we try to create rectangle with negative width
        let _rect = Rectangle::new(-10, 10);
        assert!(_rect.is_err());
    }

    #[test]
    fn negative_height() {
        // This test should check if program panics when we try to create rectangle with negative height
        let _rect = Rectangle::new(10, -10);
        assert!(_rect.is_err());
    }
}